Physioex 9 exercise 1
Simulating Dialysis (Simple Diffusion)
1. Describe two variables that affect the rate of diffusion.
The temperature of the solutions and the difference in concentration of the ion or molecule between the sides of the membrane
2. Why do you think the urea was not able to diffuse through the 20 MWCO membrane? How well did the results compare with your prediction?
Since the chemical formula for urea is (NH2)2CO and its molecular weight is about 60. It will not diffuse through the 20 MWCO membrane because it does not ionize.
3. Describe the results of the attempts to diffuse glucose and albumin through the 200 MWCO membrane. How well did the results compare with your prediction?
Glucose will diffuse through the 200 …show more content…
1. Explain in your own words why increasing the pore size increased the filtration rate. Use an analogy to support your statement.
How well did the results compare with your prediction?
Tea can pass quicker through a plastic filter with a bigger pore size as opposed to a paper filter such as the ones used in coffee makers.
2. Which solute did not appear in the filtrate using any of the membranes? Explain why.
3. Why did increasing the pressure increase the filtration rate but not the concentration of solutes? How well did the results compare with your prediction?
Increasing the filtration pressure increased the filtration rate. Nonetheless, it did not increase the amount of solute that passed through the filter. Therefore, the concentration was the same.
Simulating Active Transport
1. Describe the significance of using 9 mM sodium chloride inside the cell and 6 mM potassium chloride outside the cell, instead of other concentration ratios.
The 3 Na+ ions are transported out of the cell and 2 K+ ions are transported into the cell. This ratio of 3:2 is the same as the ratio of 9mM:6mM
2. Explain why there was no sodium transport even though ATP was present. How well did the results compare with your prediction? In order for the Na+/K+ pump to function,